A cyclone tower in the field of boiler flue gas desulphurization may present the following technical challenges. The desulphurization efficiency is relatively low (around 80%) due to short gas-liquid contact time on tower plates; CaCO3 is not suitable for use as a sulfur fixing agent; the structure of the cyclone tower is complex and is prone to the formation of filth; and The desulphurization efficiency is decreased with the increase of the tower diameter. With the cyclone tower, air is let in tangentially, and an area of low efficiency tends to form in the center. Accordingly, a rotational flow and sink flow coupling desulphurization technology is developed in the industry, which is an upgrading technology based on a pneumatic emulsification technology. The pneumatic emulsification technology is suitable for flue gas desulphurization of small boilers with significant amplification effects in amplification experiments, albeit certain constraints as well. Moreover, most of the current flue gas desulphurization technologies adopt an empty tower technology, i.e., flue gas, after entering an absorption tower, directly reacts with slurry sprayed from above without passing through the device. Thus, the flue gas and slurry are in short circuit, some flue gas leaves the absorption tower before reaction, and the flue gas has short residence duration, thereby resulting in low desulphurization efficiency.